Nitroglycerin has long been used for the internal treatment of ischemic heart diseases. Nitroglycerin has been administered in the form of various preparations such as intravenous injection, sublingual tablets and ointments. The duration of the effects of intravenous injections, sublingual tablets and ointments are several minutes, 20-30 minutes and 3-5 hours, respectively.
Generally, sublingual tablets are used for the treatment of angina pectoris. However, their effects are short lived, and the sublingual tablets are therefore unsuitable for preventing an attach.
A nitroglycerin-containing ointment is used when the effects of nitroglycerin are to be maintained for a long period of time (for example, in preventing angina pectoris). When ointment is used, a suitable amount of the ointment is applied to the skin of the patient's chest and is then covered with a plastic film or the like and to prevent the volatilization of the nitroglycerin and staining of his clothes. The suitable amount of ointment is an amount slightly smaller than that which causes a headache. The ointment is applied in various amounts to the respective patients to determine the proper amount experimentally. At present, the amount of ointment is estimated from the length of the bead extruded from the tube, so determination of the precise quantity of the ointment is difficult. Further, the use of ointment is troublesome as described above.